Even if you're lost, Rosum will find you. That's the promise of the Redwood City start-up that has figured out how to use television signals to track your whereabouts.
Rosum's technology complements the satellite-based global positioning system. The decades-old GPS, originally built for military purposes, can get a fix on gadgets equipped with GPS receivers -- as long as you're out in the open. But GPS doesn't work well in skyscraper-filled urban canyons and it doesn't work at all inside buildings.
But TV signals penetrate through buildings, and Rosum uses them to track people where GPS can't. The first device using Rosum's technology is in the prototype stage. Navigation products using it will make their debut next year, according to Rosum Chief Executive Skip Speaks.
"There are immense black holes in the GPS system, and we can fill the gap," says John Metzler, Rosum's director of business development.
Rosum, which counts among its investors In-Q-Tel, the investment arm of the Central Intelligence Agency, promises a vast improvement in location-tracking services and gadgets. That could help everyone from the military to dispatchers tracking delivery trucks. It could even be used to track parolees like Martha Stewart when they go indoors, or locate someone making a 911 emergency call on an Internet phone.
"If you are tracking a van going up the 101, it goes dark in the financial district," says Metzler. "With us, you can have the security of knowing where the van is, and if the driver has stopped to get doughnuts."
Adds Speaks, the former head of Kyocera's wireless phone business, "Ultimately, we'd like to drive the technology into every cell phone."
But privacy advocates raise a red flag about how Rosum's technology could be used to locate and track people without their consent.
Kurt Opsahl, staff attorney at the Electronic Frontier Foundation in San Francisco, said Rosum apparently will operate a location server that will be able to record the movement history of any device being tracked. If the Rosum technology eventually is built into cell phones or other popular gadgets, the government could subpoena Rosum's customers to track anyone's movements.
"This is another step toward a surveillance society," said Opsahl. "They could get your traffic patterns. This is fairly sensitive information."
Speaks says it will be up to Rosum's customers to decide how to implement the technology and balance privacy concerns. He says anyone tracking a specific person without that individual's approval must obtain a court order.
"We will give up some of our privacy for enhanced security," he says.
He notes, for instance, that a Rosum network could be set up to monitor the locations of soldiers, police or firefighters as they go into dangerous buildings. If they need to be rescued, it would be easier to locate them with the Rosum technology.
Commercial use of GPS satellites began in 1991 but James Spilker, one of the original architects of the GPS satellite, knew its weakness well.
Spilker, the founder of Stanford Telecommunications, launched Rosum in 2000 with Stanford University engineering Professor Matthew Rabinowtiz. They realized a synchronization feature in digital and analog television signals could be used for other purposes than to lock the vertical hold for older TVs.